Haochen worked on the MeiH10/RPI-EventHub repository, focusing on enhancing the user experience for the Event Details page by implementing a loading skeleton UI. Using React and JavaScript with JSX, Haochen replaced the static 'Event not found' message with a dynamic visual loading indicator, introducing a new state variable and conditional rendering to manage the loading state during data fetches. This approach provided immediate feedback to users, reducing perceived latency and improving engagement. The work addressed a specific frontend challenge, demonstrating a solid understanding of state management and user interface responsiveness, though it was limited in scope to a single feature.